Electronic components have found wide applications in various kinds of electronic equipment and communication devices. With recent size and cost reduction of electronic components, it is becoming more important to reduce the size and cost of ceramic elements for use in bobbins, core materials, or base materials thereof as well.
Conventionally, these ceramic bodies have been manufactured by powder molding. The powder molding process includes the steps of: adding a binder to a ceramic raw material; forming ceramic granules in a granulation process; filling the ceramic granules in a mold; molding the granules by uniaxially pressing followed by a sintering of the molded object.
In the powder molding process, ceramic granules must be filled in a mold evenly. Unevenly filled granules cause problems, such as improper pressing, incorrect height, and moreover, breakdown of the pins or the mold. Furthermore, in the case of a small and complicated shaped component, filling granules in every corner of the mold is difficult. Increasing molding pressure to efficiently fill the granules causes problems, such as breakdown of the mold.
As described above, in the powder molding process, it is essential to fill ceramic granules in a mold evenly. For this purpose, powder fluidity of the ceramic granules is important. Ceramic granules have excellent powder fluidity when they are spherical and have diameters of at least 100 μm. In addition, for the granules to be filled evenly, the mold must have a size more than ten times the diameter of each granule.
However, with the downsizing of ceramic elements, it has become difficult to satisfy the necessary conditions for ensuring the relationship between the mold size and the diameter of the ceramic granule, and powder fluidity. In addition, for cost reduction of the products, it is necessary to use a multi-cavity mold. However, granules tend to be filled in the multi-cavity mold more unevenly. Therefore, it is difficult to obtain a smaller ceramic element and cost reduction thereof at the same time.
The present invention addresses the conventional problems discussed above. Therefore, it is an object of the present invention to provide a manufacturing method in which small ceramic elements can be produced at a low cost by punching a ceramic sheet using a face-forming mold of a multi-pin structure and cutting the ceramic sheet into separate pieces.